Throstle Nest

Came across this sign at the end of Tom Bell Lane heading towards Throstle Nest. I thought the trail to Throslte Nest was open - have the authorities forgotten to take the sign down? How passable is the lane to Throstle Nest?

Rode it yesterday - Tom Bell Lane is muddy and overgrown but the path to Throstle Nest is still very passable. The signs have not changed from the picture in my original posting. No blue signs at either end of the lane.